* [PATCH v2 0/2] Fix segfault in qemu_rbd_parse_filename
@ 2021-04-01 21:01 Connor Kuehl
2021-04-01 21:01 ` [PATCH v2 1/2] iotests/231: Update expected deprecation message Connor Kuehl
2021-04-01 21:01 ` [PATCH v2 2/2] block/rbd: Add an escape-aware strchr helper Connor Kuehl
0 siblings, 2 replies; 6+ messages in thread
From: Connor Kuehl @ 2021-04-01 21:01 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, dillaman, qemu-devel, mreitz
Replaced the change to qemu_rbd_next_tok with a standalone escape-aware
helper for patch 2.
Connor Kuehl (2):
iotests/231: Update expected deprecation message
block/rbd: Add an escape-aware strchr helper
block/rbd.c | 20 ++++++++++++++++++--
tests/qemu-iotests/231 | 4 ++++
tests/qemu-iotests/231.out | 7 ++++---
3 files changed, 26 insertions(+), 5 deletions(-)
--
2.30.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 1/2] iotests/231: Update expected deprecation message
2021-04-01 21:01 [PATCH v2 0/2] Fix segfault in qemu_rbd_parse_filename Connor Kuehl
@ 2021-04-01 21:01 ` Connor Kuehl
2021-04-01 21:01 ` [PATCH v2 2/2] block/rbd: Add an escape-aware strchr helper Connor Kuehl
1 sibling, 0 replies; 6+ messages in thread
From: Connor Kuehl @ 2021-04-01 21:01 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, dillaman, qemu-devel, mreitz
The deprecation message in the expected output has technically been
wrong since the wrong version of a patch was applied to it. Because of
this, the test fails. Correct the expected output so that it passes.
Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
Reworded the commit log and added Max's R-b.
tests/qemu-iotests/231.out | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/tests/qemu-iotests/231.out b/tests/qemu-iotests/231.out
index 579ba11c16..747dd221bb 100644
--- a/tests/qemu-iotests/231.out
+++ b/tests/qemu-iotests/231.out
@@ -1,9 +1,7 @@
QA output created by 231
-qemu-img: RBD options encoded in the filename as keyvalue pairs is deprecated. Future versions may cease to parse these options in the future.
+qemu-img: warning: RBD options encoded in the filename as keyvalue pairs is deprecated
unable to get monitor info from DNS SRV with service name: ceph-mon
-no monitors specified to connect to.
qemu-img: Could not open 'json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=BOGUS_CONF'}': error connecting: No such file or directory
unable to get monitor info from DNS SRV with service name: ceph-mon
-no monitors specified to connect to.
qemu-img: Could not open 'json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'BOGUS_CONF'}': error connecting: No such file or directory
*** done
--
2.30.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] block/rbd: Add an escape-aware strchr helper
2021-04-01 21:01 [PATCH v2 0/2] Fix segfault in qemu_rbd_parse_filename Connor Kuehl
2021-04-01 21:01 ` [PATCH v2 1/2] iotests/231: Update expected deprecation message Connor Kuehl
@ 2021-04-01 21:01 ` Connor Kuehl
2021-04-06 14:24 ` Max Reitz
1 sibling, 1 reply; 6+ messages in thread
From: Connor Kuehl @ 2021-04-01 21:01 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, dillaman, qemu-devel, mreitz
Sometimes the parser needs to further split a token it has collected
from the token input stream. Right now, it does a cursory check to see
if the relevant characters appear in the token to determine if it should
break it down further.
However, qemu_rbd_next_tok() will escape characters as it removes tokens
from the token stream and plain strchr() won't. This can make the
initial strchr() check slightly misleading since it implies
qemu_rbd_next_tok() will find the token and split on it, except the
reality is that qemu_rbd_next_tok() will pass over it if it is escaped.
Use a custom strchr to avoid mixing escaped and unescaped string
operations.
Reported-by: Han Han <hhan@redhat.com>
Fixes: https://bugzilla.redhat.com/1873913
Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
---
block/rbd.c | 20 ++++++++++++++++++--
tests/qemu-iotests/231 | 4 ++++
tests/qemu-iotests/231.out | 3 +++
3 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/block/rbd.c b/block/rbd.c
index 9071a00e3f..c0e4d4a952 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -134,6 +134,22 @@ static char *qemu_rbd_next_tok(char *src, char delim, char **p)
return src;
}
+static char *qemu_rbd_strchr(char *src, char delim)
+{
+ char *p;
+
+ for (p = src; *p; ++p) {
+ if (*p == delim) {
+ return p;
+ }
+ if (*p == '\\') {
+ ++p;
+ }
+ }
+
+ return NULL;
+}
+
static void qemu_rbd_unescape(char *src)
{
char *p;
@@ -171,7 +187,7 @@ static void qemu_rbd_parse_filename(const char *filename, QDict *options,
qemu_rbd_unescape(found_str);
qdict_put_str(options, "pool", found_str);
- if (strchr(p, '@')) {
+ if (qemu_rbd_strchr(p, '@')) {
image_name = qemu_rbd_next_tok(p, '@', &p);
found_str = qemu_rbd_next_tok(p, ':', &p);
@@ -181,7 +197,7 @@ static void qemu_rbd_parse_filename(const char *filename, QDict *options,
image_name = qemu_rbd_next_tok(p, ':', &p);
}
/* Check for namespace in the image_name */
- if (strchr(image_name, '/')) {
+ if (qemu_rbd_strchr(image_name, '/')) {
found_str = qemu_rbd_next_tok(image_name, '/', &image_name);
qemu_rbd_unescape(found_str);
qdict_put_str(options, "namespace", found_str);
diff --git a/tests/qemu-iotests/231 b/tests/qemu-iotests/231
index 0f66d0ca36..8e6c6447c1 100755
--- a/tests/qemu-iotests/231
+++ b/tests/qemu-iotests/231
@@ -55,6 +55,10 @@ _filter_conf()
$QEMU_IMG info "json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=${BOGUS_CONF}'}" 2>&1 | _filter_conf
$QEMU_IMG info "json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'${BOGUS_CONF}'}" 2>&1 | _filter_conf
+# Regression test: the qemu-img invocation is expected to fail, but it should
+# not seg fault the parser.
+$QEMU_IMG create "rbd:rbd/aa\/bb:conf=${BOGUS_CONF}" 1M 2>&1 | _filter_conf
+
# success, all done
echo "*** done"
rm -f $seq.full
diff --git a/tests/qemu-iotests/231.out b/tests/qemu-iotests/231.out
index 747dd221bb..a785a6e859 100644
--- a/tests/qemu-iotests/231.out
+++ b/tests/qemu-iotests/231.out
@@ -4,4 +4,7 @@ unable to get monitor info from DNS SRV with service name: ceph-mon
qemu-img: Could not open 'json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=BOGUS_CONF'}': error connecting: No such file or directory
unable to get monitor info from DNS SRV with service name: ceph-mon
qemu-img: Could not open 'json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'BOGUS_CONF'}': error connecting: No such file or directory
+Formatting 'rbd:rbd/aa\/bb:conf=BOGUS_CONF', fmt=raw size=1048576
+unable to get monitor info from DNS SRV with service name: ceph-mon
+qemu-img: rbd:rbd/aa\/bb:conf=BOGUS_CONF: error connecting: No such file or directory
*** done
--
2.30.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] block/rbd: Add an escape-aware strchr helper
2021-04-01 21:01 ` [PATCH v2 2/2] block/rbd: Add an escape-aware strchr helper Connor Kuehl
@ 2021-04-06 14:24 ` Max Reitz
2021-04-09 14:05 ` Connor Kuehl
0 siblings, 1 reply; 6+ messages in thread
From: Max Reitz @ 2021-04-06 14:24 UTC (permalink / raw)
To: Connor Kuehl, qemu-block; +Cc: kwolf, dillaman, qemu-devel
On 01.04.21 23:01, Connor Kuehl wrote:
> Sometimes the parser needs to further split a token it has collected
> from the token input stream. Right now, it does a cursory check to see
> if the relevant characters appear in the token to determine if it should
> break it down further.
>
> However, qemu_rbd_next_tok() will escape characters as it removes tokens
> from the token stream and plain strchr() won't. This can make the
> initial strchr() check slightly misleading since it implies
> qemu_rbd_next_tok() will find the token and split on it, except the
> reality is that qemu_rbd_next_tok() will pass over it if it is escaped.
>
> Use a custom strchr to avoid mixing escaped and unescaped string
> operations.
>
> Reported-by: Han Han <hhan@redhat.com>
> Fixes: https://bugzilla.redhat.com/1873913
> Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
> ---
> block/rbd.c | 20 ++++++++++++++++++--
> tests/qemu-iotests/231 | 4 ++++
> tests/qemu-iotests/231.out | 3 +++
> 3 files changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/block/rbd.c b/block/rbd.c
> index 9071a00e3f..c0e4d4a952 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -134,6 +134,22 @@ static char *qemu_rbd_next_tok(char *src, char delim, char **p)
> return src;
> }
>
> +static char *qemu_rbd_strchr(char *src, char delim)
> +{
> + char *p;
> +
> + for (p = src; *p; ++p) {
> + if (*p == delim) {
> + return p;
> + }
> + if (*p == '\\') {
> + ++p;
> + }
> + }
> +
> + return NULL;
> +}
> +
So I thought you could make qemu_rbd_do_next_tok() to do this. (I
didn’t say you should, but bear with me.) That would be possible by
giving it a new parameter (e.g. @find), and if that is set, return @end
if *end == delim after the loop, and NULL otherwise.
Now, if you add wrapper functions to make it nice, there’s not much more
difference in lines added compared to just adding a new function, but it
does mean your function should basically be the same as
qemu_rbd_next_tok(), except that no splitting happens, that there is no
*p, and that @end is returned instead of @src.
So there is one difference, and that is that qemu_rbd_next_tok() has
this condition to skip escaped characters:
if (*end == '\\' && end[1] != '\0') {
where qemu_rbd_strchr() has only:
if (*p == '\\') {
And I think qemu_rbd_next_tok() is right; if the string in question has
a trailing backslash, qemu_rbd_strchr() will ignore the final NUL and
continue searching past the end of the string.
Max
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] block/rbd: Add an escape-aware strchr helper
2021-04-06 14:24 ` Max Reitz
@ 2021-04-09 14:05 ` Connor Kuehl
2021-04-09 14:19 ` Max Reitz
0 siblings, 1 reply; 6+ messages in thread
From: Connor Kuehl @ 2021-04-09 14:05 UTC (permalink / raw)
To: Max Reitz, qemu-block; +Cc: kwolf, dillaman, qemu-devel
On 4/6/21 9:24 AM, Max Reitz wrote:
> On 01.04.21 23:01, Connor Kuehl wrote:
>> [..]
>> diff --git a/block/rbd.c b/block/rbd.c
>> index 9071a00e3f..c0e4d4a952 100644
>> --- a/block/rbd.c
>> +++ b/block/rbd.c
>> @@ -134,6 +134,22 @@ static char *qemu_rbd_next_tok(char *src, char
>> delim, char **p)
>> return src;
>> }
>> +static char *qemu_rbd_strchr(char *src, char delim)
>> +{
>> + char *p;
>> +
>> + for (p = src; *p; ++p) {
>> + if (*p == delim) {
>> + return p;
>> + }
>> + if (*p == '\\') {
>> + ++p;
>> + }
>> + }
>> +
>> + return NULL;
>> +}
>> +
>
> So I thought you could make qemu_rbd_do_next_tok() to do this. (I
> didn’t say you should, but bear with me.) That would be possible by
> giving it a new parameter (e.g. @find), and if that is set, return @end
> if *end == delim after the loop, and NULL otherwise.
>
> Now, if you add wrapper functions to make it nice, there’s not much more
> difference in lines added compared to just adding a new function, but it
> does mean your function should basically be the same as
> qemu_rbd_next_tok(), except that no splitting happens, that there is no
> *p, and that @end is returned instead of @src.
Do you have a strong preference for this? I agree that
qemu_rbd_next_tok() could grow this functionality, but I think it'd be
simpler to keep it separate in the form of qemu_rbd_strchr().
>
> So there is one difference, and that is that qemu_rbd_next_tok() has
> this condition to skip escaped characters:
>
> if (*end == '\\' && end[1] != '\0') {
>
> where qemu_rbd_strchr() has only:
>
> if (*p == '\\') {
>
> And I think qemu_rbd_next_tok() is right; if the string in question has
> a trailing backslash, qemu_rbd_strchr() will ignore the final NUL and
> continue searching past the end of the string.
Aha, good catch. I'll fix this up.
Thank you,
Connor
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] block/rbd: Add an escape-aware strchr helper
2021-04-09 14:05 ` Connor Kuehl
@ 2021-04-09 14:19 ` Max Reitz
0 siblings, 0 replies; 6+ messages in thread
From: Max Reitz @ 2021-04-09 14:19 UTC (permalink / raw)
To: Connor Kuehl, qemu-block; +Cc: kwolf, dillaman, qemu-devel
On 09.04.21 16:05, Connor Kuehl wrote:
> On 4/6/21 9:24 AM, Max Reitz wrote:
>> On 01.04.21 23:01, Connor Kuehl wrote:
>>> [..]
>>> diff --git a/block/rbd.c b/block/rbd.c
>>> index 9071a00e3f..c0e4d4a952 100644
>>> --- a/block/rbd.c
>>> +++ b/block/rbd.c
>>> @@ -134,6 +134,22 @@ static char *qemu_rbd_next_tok(char *src, char
>>> delim, char **p)
>>> return src;
>>> }
>>> +static char *qemu_rbd_strchr(char *src, char delim)
>>> +{
>>> + char *p;
>>> +
>>> + for (p = src; *p; ++p) {
>>> + if (*p == delim) {
>>> + return p;
>>> + }
>>> + if (*p == '\\') {
>>> + ++p;
>>> + }
>>> + }
>>> +
>>> + return NULL;
>>> +}
>>> +
>>
>> So I thought you could make qemu_rbd_do_next_tok() to do this. (I
>> didn’t say you should, but bear with me.) That would be possible by
>> giving it a new parameter (e.g. @find), and if that is set, return
>> @end if *end == delim after the loop, and NULL otherwise.
>>
>> Now, if you add wrapper functions to make it nice, there’s not much
>> more difference in lines added compared to just adding a new function,
>> but it does mean your function should basically be the same as
>> qemu_rbd_next_tok(), except that no splitting happens, that there is
>> no *p, and that @end is returned instead of @src.
>
> Do you have a strong preference for this? I agree that
> qemu_rbd_next_tok() could grow this functionality, but I think it'd be
> simpler to keep it separate in the form of qemu_rbd_strchr().
Oh, no, no. I mostly said this so it would be clear why both functions
should basically have the same structure, i.e. why a difference in
structure might be a sign that something’s wrong.
Sorry if I came across as too verbose.
>> So there is one difference, and that is that qemu_rbd_next_tok() has
>> this condition to skip escaped characters:
>>
>> if (*end == '\\' && end[1] != '\0') {
>>
>> where qemu_rbd_strchr() has only:
>>
>> if (*p == '\\') {
>>
>> And I think qemu_rbd_next_tok() is right; if the string in question
>> has a trailing backslash, qemu_rbd_strchr() will ignore the final NUL
>> and continue searching past the end of the string.
>
> Aha, good catch. I'll fix this up.
Thanks!
Max
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-04-09 14:21 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-04-01 21:01 [PATCH v2 0/2] Fix segfault in qemu_rbd_parse_filename Connor Kuehl
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2021-04-01 21:01 ` [PATCH v2 2/2] block/rbd: Add an escape-aware strchr helper Connor Kuehl
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